<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript">
        let x = 2;
        console.log(typeof x);
        console.log(window);
        let timeout = setTimeout(function () {
            console.log("5s后");
        },5000);

        function clearTime() {
            clearTimeout(timeout);
            console.log(typeof timeout);
        }
    </script>
</head>
<body>
<button onclick="clearTime()">点击清除计时</button>
</body>
</html>